OS 15 LA SILVER RC ENGINE WITH SILENCER Features Overall tighter needle valve fit utilizes an "O" ring to help maintain the performance levels you need A fuel inlet that points up allows for easier fuel line access for fueling and defueling More cooling fin area extends the life of the engine and virtually eliminates engine seizures in the air. Added "webbing" on the crankcase strengthens high-stress areas to help ensure that they stand up to the rigors of learning to fly Displacement 0.152cu.in. (2.49cc) Output 0.41ps/17000rpm Practical RPM 2500~18000 Weight 138g Prop 7 x 5~6, 8 x 4~5 Brand OS Engines